In the related art, there is known a tape cartridge which is mounted in an apparatus body provided with an optical sensor, the tape cartridge including a label tape having a detection target part whose a lateral side protrudes in a tape width direction and a cartridge case which contains a tape roll around which the label tape is wound in a roll shape. An outer surface of the cartridge case is provided with an exposed area in which the detection target part is exposed such that the passage of the detection target part is detected by the optical sensor when the label tape is delivered from the tape roll in a state where the tape cartridge is mounted on the apparatus body. Further, the cartridge case has a tape cover, which covers the front and back of the detection target part of the label tape delivered from the tape roll, on a tape feeding upstream side from the exposed area (see Patent Literature 1).